2-Way Directional Control Valve - MapleSim Help

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2-Way Directional Control Valve

Valve that allows flow between four ports and two positions based on the flow path specified

Description

A 2-way Directional Control Valve allows flow between four ports A, B, P, T with two positions to allow the flow through them. There are four orifices inter-connected to each other which opens up according to the input feed thereby allowing fluid to flow between the different port. A generic form allows the user to specify the custom scenario according to the need. Based on the orifice area, the pressure vs. flow rate relationship is calculated by the formulation used in the Orifice component.

The input s controls the position of the value. An input of 0 corresponds to position 0, an input of 1 to position 1.  Intermediates values produce an averaged position, with the transition length set by the Band parameter.

Same representation is followed for all types of Directional control components .

Component

Representation

Signal and flow path

 0 P -> A (open) B-> T (open) 1 P -> B (open) A -> T (open)

 0 All ports closed 1 P -> A (open) B -> T (open)

Flow paths can be customized under the parameters

Variables

 Name Units Description Modelica ID $\mathrm{p__X}$ $\mathrm{Pa}$ Pressure at port X, X∈{A, B, P,T} pX $\mathrm{q__X}$ $\frac{{m}^{3}}{s}$ Flow rate into port X, X∈{A, B, P,T} qX

Connections

 Name Description Modelica ID $\mathrm{portA}$ Hydraulic port to path A portA $\mathrm{portB}$ Hydraulic port path B portB $\mathrm{portP}$ Hydraulic port for Pump portP $\mathrm{portT}$ Hydraulic port for Tank portT s Real input signal that sets valve position s

Parameters

 Name Default Units Description Modelica ID $\mathrm{A__max}$ $0.001$ ${m}^{2}$ Maximum orifice opening area Amax $\mathrm{A__min}$ $1.0·{10}^{-12}$ ${m}^{2}$ Minimum orifice opening area (leakage) Amin $\mathrm{C__d}$ $0.7$ $-$ Flow-discharge coefficient Cd $\mathrm{ℜ__Cr}$ $12$ $-$ Reynolds number at critical flow ReCr $\mathrm{Band}$ 0.1 - Transition length in normalized spool displacement band [0,1] - Pump to path A (generic model) sPA [1,0] - Pump to path B (generic model) sPB $\mathrm{s__T−A}$ [1,0] - Tank to path A (generic model) sTA $\mathrm{s__T−B}$ [0,1] - Tank to path B (generic model) sTB $\mathrm{s__A−B}$ [0,0] - Path A to B (generic model) sAB $\mathrm{s__P−T}$ [0,0] - Path pump to tank (generic model) sPT

Volumes

 Name Default Units Description Modelica ID $\mathrm{false}$ $-$ When true a hydraulic volume chamber is added to port A useVolumeA $\mathrm{V__A}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber at port A Va $\mathrm{false}$ $-$ When true a hydraulic volume chamber is added to port B useVolumeB $\mathrm{V__B}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber at port B Vb $\mathrm{false}$ $-$ When true a hydraulic volume chamber is added to port P useVolumeP $\mathrm{V__P}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber at port P Vp $\mathrm{false}$ $-$ When true a hydraulic volume chamber is added to port T useVolumeT $\mathrm{V__T}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber at port T Vt

For more information see Hydraulic Volume Equations

 See Also